I Stepped on a Gecko to Death, and the System Said I Killed a Dragon?

Ding, congratulations to the host for leapfrogging and slaying the Beast King-level beast - the Immortal Dragon. The reward will be increased a hundred times. Awakening of supernatural powers - immortality. Reward one hundred years of cultivation. Gu Yi stared blankly at the gecko on the ground that had been crushed by his kick. This gadget is the beast king who claims to be fearless of any hot weapons under missiles? Or some kind of immortal dragon? Gu Yi: It's broken, it's coming for me. Bad news: The system seems a bit unreliable. Good news: He seems to have arrived early, well... Maybe a hundred years early. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.